Thermofit forged upper receivers

[SDW]

^^^ Actually, if you're talking about the Vltor MUR upper, it's forged, not billet. Just made beefer/thicker. Then machined to a high standard where needed. And they're not thermal fit. I have two of them. For both, the barrels slipped in without much fuss. With one barrel I shimmed the barrel extension with brass shim stock to get a nice, tight fit. For the other it was a little too tight for shimming so I left it alone.